The photo recalls a famous 2016 selfie taken by two North and South Korean gymnasts at the Rio Olympics - something that IOC President Thomas Bach described as a "great gesture".
These officials said that while Pence did not greet Kim Yong Nam, he didn't deliberately skip over him.
"There was no problem with their costumes but they entered the media seats with a regular ticket", they said.
The invitation was personally delivered on Saturday (Feb 10) by Mr Kim's younger sister Yo Jong, who visited Seoul as a special envoy of the North Korean leader.
But organizers of the Winter Games in Pyeongchang - which opened with a spectacle heavy with lore and symbols binding North and South Korea - have emphasized them heavily as a chance to find a new path for neighbors frozen in a Cold War-era standoff.
Moon and the two North Korean delegates cheerfully clapped and waved as the athletes from the two Koreas jointly marched during the ceremony holding a blue-and-white flag symbolizing a unified Korean Peninsula.
Washington has pursued a strategy of exerting maximum pressure on Pyongyang through tough sanctions and harsh rhetoric, demanding it give up its pursuit of nuclear weapons first for any dialogue to occur.
At an emergency meeting of the United Nations Security Council in December, the U.S. ambassador to the UN, Nikki Haley, warned that "if war comes, make no mistake, the North Korean regime will be utterly destroyed".
Officials traveling with Pence said it would be fair to characterize his failure to interact with the North Koreans as a mutual decision, with neither side making any public overtures. They may also see a performance by a visiting North Korean art troupe in Seoul on Sunday before flying back to Pyongyang.
Moon's office says the North Korean delegates were served traditional food from the Gangwon province, a mountainous coastal area that's home to the Olympic towns of Pyeongchang and Gangneung. About 500 North Koreans, including 22 athletes, have traveled south for the Games, which will wrap up February 25.
"People told us it was really amusing", he said. On Feb. 14, the Korean team faces Japan, which colonized Korea for more than three decades before it split into North and South shortly after World War II.
"She's a pretty important person in the regime", said Michael Madden, an analyst at the U.S. -Korea Institute at the Johns Hopkins School of Advanced International Studies.
Deepening the odd-man-out optics for Pence, Moon and Kim, smiling broadly, exchanged a handshake and cheered the team enthusiastically.
"Our training, which included the lecture as well as our one-page guidelines, was aimed at preventing any potential conflicts that could arise from cultural differences", the official said, speaking on condition of anonymity due to the sensitivity of the issue.
"For our team meetings it is going through to English to South Korean to North Korean".